- a bag of snacks. Poppers, frozen water bottles, sangers (pop in ice bricks if it's hot). It will save you a FORTUNE over the course of the trip and you won't have kids in your ear trying to find the next servo.
- DVD player/tablet/ipod - My sanity was saved on a recent trip. DH put movies onto their tablets, about 10 each. Then we attached ear phones. It kept them happy and minimised the 12000 Are We There Yet?'s.
Take a Tom Tom - nothing more stressful then trying to navigate while kids are fighting in the back. That device was brilliant on our trip to a capital city.